Ink composition and image-forming method using the same

Abstract

An ink composition comprising an aqueous medium having dispersed therein a coloring fine particle dispersion, wherein the coloring fine particle dispersion contains a hydrophobic ethylenically unsaturated monomer and at least one oil-soluble dye, and the ink composition contains apolymerization initiator.

What is claimed is:  
     
         1 . An ink composition comprising an aqueous medium having dispersed therein a coloring fine particle dispersion, wherein the coloring fine particle dispersion contains a hydrophobic ethylenically unsaturated monomer and at least one oil-soluble dye, and the ink composition contains a polymerization initiator.  
     
     
         2 . An image-forming method comprising the steps of: printing by using the ink composition comprising an aqueous medium having dispersed therein a coloring fine particle dispersion in which the coloring fine particle dispersion contains a hydrophobic ethylenically unsaturated monomer and at least one oil-soluble dye, and the ink composition contains a polymerization initiator; and then polymerizing the hydrophobic ethylenically unsaturated monomer.  
     
     
         3 . A manufacturing method of the ink composition comprising an aqueous medium having dispersed therein a coloring fine particle dispersion in which the coloring fine particle dispersion contains a hydrophobic ethylenically unsaturated monomer and at least one oil-soluble dye, and the ink composition contains a polymerization initiator; wherein the method comprises the step of obtaining the coloring fine particle dispersion by emulsification of a solution containing the hydrophobic ethylenically unsaturated monomer and at least one oil-soluble dye in the aqueous dispersion.  
     
     
         4 . The ink composition as claimed in  claim 1 , wherein the oil-soluble dye is represented by the following formula (I):  
       
         
           
           
               
               
           
         
       
       wherein X represents the residue of a color photographic coupler; A represents —NR 4 R 5  or a hydroxyl group; R 4  and R 5  each represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group; B 1  represents ═C (R 6 )—or ═N—; B 2  represents —C(R 7 )═or —N═; R 2 , R 3 , R 6  and R 7  each represents a hydrogen atom, a halogen atom, an aliphatic group, an aromatic group, a heterocyclic group, a cyano group, —OR 51 , —SR 52 , —CO 2 R 53 , —OCOR 54 , —NR R 55 R 56 , —CONR 75 R 58 , —SO 2 R 59 , —SO 2 NR 60 R 61 , —NR 62 CONR 63 R 64 , NR 65 CO 2 R 66 , —COR 67 , —NR 68 COR 69  or —NR 70 SO 2 R 71 ; R 51 , R 52 , R 53 , R 54 , R 55 , R 56 , R 57 , R 58 , R 59 , R 60 , R 61 , R 62 , R 63 , R 64 , R 65 , R 66 , R 67 , R 68 , R 69 , R 70  and R 71  each represents a hydrogen atom, an aliphatic group or an aromatic group; and R 2  and R 3 , R 3  and R 4 , R 4  and R5, R 5  and R 6  and R 6  and R  7 may be bonded to each other to form a ring.  
     
     
         5 . The ink composition as claimed in  claim 1 , wherein the content of the hydrophobic ethylenically unsaturated monomer in the coloring fine particles is 25 mass % or more.  
     
     
         6 . The ink composition as claimed in  claim 1 , wherein the polymerization initiator is contained in the coloring fine particles.  
     
     
         7 . The ink composition as claimed in  claim 1 , wherein the polymerization initiator is an initiator which generates radicals by heating or ultraviolet irradiation.  
     
     
         8 . The ink composition as claimed in  claim 1 , wherein the boiling point of the hydrophobic ethylenically unsaturated monomer is 150° C. or higher.  
     
     
         9 . The ink composition as claimed in  claim 1 , wherein the average particle diameter of the coloring fine particles in the coloring fine particle dispersion is 500 nm or less.  
     
     
         10 . The ink composition as claimed in  claim 1 , which: has viscosity of 10 mPa.s or less.  
     
     
         11 . The image-forming method as claimed in  claim 2 , wherein the ink composition is used for recording on the image-receiving material comprising a support having thereon an ink-receiving layer containing a porous inorganic pigment.